January 16, 2026
TV mount, big volts, bigger opinions
Local-only Marstek Venus e-battery integration with Home Assistant
€1k DIY battery goes cloud‑free on a TV mount — and sparks a plug‑power brawl
TLDR: A €1k, 5 kWh battery was wired for local, no‑cloud control via Home Assistant to boost solar self‑use, aiming for a six‑year payoff. Comments erupted over schuko socket limits and a tip that the newer model supports network control natively, sparking safety vs. simplicity debates that every DIYer should see.
A solar DIYer strapped a budget 5 kWh battery to the wall with a TV bracket, cut the cloud umbilical cord, and wired it into Home Assistant for full local control — and the crowd went wild. Fans cheered the “no app, no data mining” stance and loved the price: about €1,049 for a setup aiming to boost self‑consumption from roughly 50% to about 78%, with a six‑year payback. The vibe? Privacy purists high‑fiving, tinkerers swooning over the Modbus (a simple device‑to‑device language) control loop, and everyone giggling that a TV mount just graduated to “energy hardware.”
Then came the drama. One camp lit up the comments arguing about the humble schuko (that everyday European wall socket): is 800 W “safe conservative,” or needless hand‑wringing? Rygian bragged about charging a car at 10 A; safety hawks clapped back about heat, wiring, and national codes. Meanwhile, t0mas88 crashed the party with a firmware mic‑drop: the newer Marstek Venus E 3.0 speaks Modbus over normal network right out of the box — no RS485 converter needed. Cue the “overengineering” jokes, “Home Assistant or Home Electrician?” memes, and a side debate over whether zero‑export control loops will placate utilities. It’s thrifty, it’s nerdy, it’s chaotic — and the comments are the show.
Key Points
- •Integration of a Marstek Venus E 2.0 5.12 kWh AC-coupled battery into a 30 kWp PV system with local-only control.
- •Objective is zero-cloud dependency, using RS485 and Modbus TCP via Home Assistant for a zero-export regulation loop.
- •Economic assumptions: electricity at €0.32/kWh, feed-in at €0.082/kWh; projected self-consumption increase to ~78% and ~6-year ROI.
- •Hardware setup includes a One-For-All Solid WM4411 TV mount and a Waveshare RS485-to-Ethernet converter with defined wiring pinout.
- •Software architecture: Raspberry Pi Zero WH + IR/vzlogger to MQTT, Home Assistant computes control and issues Modbus TCP commands to the battery.